DE1911263A1 - Process for the production of adipic acid nitrile - Google Patents

Description

Process for the preparation of adiponitrile

The invention relates to a method of manufacture of adiponitrile from adipic acid and ammonia using a fluidized bed or fluidized bed, since Contains particles of a dehydration catalyst. In particular, the invention relates to a process for the production of adipic acid nitrile, wherein an aqueous solution of adipic acid from a spray nozzle as hot aqueous · Solution of adipic acid, which is attached in the central part of a funnel-shaped distributor at the bottom of the «fluidized bed, is sprayed» and «into part of the hot ammonia gas in the form of a single gas nozzle stream Fluidized bed from an injection opening around the nozzle is attached around »is injected»

Ss is already a process for the production of Adipic acid nitrile known »where previously evaporated · Adipic acid and ammonia gas in the gas phase in the presence a · dehydration catalysta brought into contact will. However, when performing the above Process · Cyclopentanone as a by-product by di · during evaporation of adipic acid and introduction of the evaporated adipic acid in da · R * aktlonag «fäd ν · Γ-

009834/1933

caused decarboxylation and will continue to be Cyanoimines formed as by-products in the reaction vessel. Under the reaction conditions, these by-products favor the deposition of carbon-containing substances on the catalyst surface, which are the main factor in the damage to the catalyst, see above that the life of the catalyst is shortened. Therefore, there are complicated steps to separate them By-products and required to purify the crude adiponitrile. Therefore, this method is industrially disadvantageous.

To avoid the disadvantages of the process with the introduction of adipic acid in the steam » In order to avoid shape, American patent 3 242 204 describes a process for the production of adipic acid nitrile, in which powdered adipic acid is placed in a fluidized bed together with ammonia gas is introduced, and the adipic acid with the ammonia in the presence of a Dehydratlsierungskatalysatore in the Fluidized bed is implemented. Although this process is satisfactory in terms of obtaining pure adiponitrile in high yields, it still has various operating problems. Included this process the adipic acid into the fluidized bed in the powdery state through the aeration process is introduced by means of the ammonia gas stream, the Adipic acid is not uniformly and sufficiently dispersed within the fluidized bed and part of the in adipic acid fed into the bed sticks in its powdery state in the area of the distributor or the reaction vessel wall, which causes the formation of carbon

009834/1933

containing substances through thermal decomposition results in »If the adipic acid is introduced into the fluidized bed in a powdery state, the adipic acid melts and sticks to a part of the adipic acid feed line, which results in disadvantages such as clogging of the feed device · So that the adipic acid is kept stable and sticking of solid or molten adipic acid in pneumatic transport of adipic acid in Pulversustand and is prevented in Adipinsäuretrichter, ee is necessary according to this method, an inert gas such as to apply nitrogen to prevent the contact of adipic acid with ammonia, and the temperature of the adipic acid less than 5Q ⁰ to keep C. If it is introduced into the fluidized bed together with the stream of ammonia, the temperature must also ammonia dee be kept below 50 ⁰ C. This gives rise to disadvantages such as accumulation of the inert gas in the reaction system and non-uniform temperature distribution in the system. Although available iet in this method Adipinsäurenitril in satisfactory Auebeuten at the initial stage of the operation _f is the decrease of the activity of the catalyst extremely strong when the operating time is prolonged. This is another disadvantage of this procedure.

In the context of extensive studies regarding the production of adiponitrile using fluidized beds has now been found that the above Described disadvantages of the known processes can be overcome and adiponitrile of high Purity can be produced in high yields without the occurrence of the operating problems listed above,

009834/1933 BAD ORiGtNAL

When an aqueous solution of adipic acid from .einer Ms © one spraying in a hot aqueous solution of adipic acid ₉ the jb raittigen part of a funnel-shaped Υθε = plate is attached to the bottom of the vertebral layer fat, and part of a 250 Ms 55O ⁰ C
heated Aranoniakgases in the form of a Sasdiisemetroiaes in the fluidized bed from a binding opening _s around this
around, is attached »imbeded WiPa _9, which means di @
torteilchen.su einer.Sonvektioiisströmimg vmä @ ia @ s "
lar flow in the bed causes what dl ©
position of the goal-lying invention represents »

Specifically, based on the invention, © in FIG
drive to the production of Adipinsäurenitrilp whereby
pinic acid and ammonia at a temperature γοη 250 to
55O ⁵ C in a fluidized bed of a solid Dehjirati = sierungskatalysators, which is fluidized by ammonia gas, are implemented, with a part eiaes aufhöh®
Temperatures of preheated Ammoiiiakgases la the fluidized bed through a funnel-shaped distributor, d @ s? is attached to the bottom of the fluidized bed? »Adipic acid is introduced in the form of a hot aqueous solution into the fluidized bed through an injection nozzle © for © in®
hot aqueous solution of adipic acid, which is present in the central part of the funnel-shaped distributor, is inserted »and the remaining ammonia gas into the fluidized bed as a gas stream from an injection opening which is attached around the injection nozzle for the hot aqueous solution of adipic acid, in a Linear speed (U * m / mk ₉ }
higher than the average surface velocity in the empty column (Uo m / sec.) of the whole
Ammonia gas is introduced, eo that the dahydration catalyst in convection and circular in the vortex

00983 ^ / 1933

BATH ORIGINAL

stratified bed flows.

According to the invention, the adipic acid is sprayed into the fluidized bed in the form of a hot aqueous solution. There is no specific limitation on the concentration of adipic acid in the aqueous solution as long as the aqueous solution is kept stable. In general, the adipic acid concentration in the aqueous solution is 70 to 95% by weight and is preferably higher than 80% by weight; Such aqueous solutions can be prepared in a stable manner by dissolving adipic acid in ^{hot water kept at 80 to 145 6} C under atmospheric pressure or under increased pressure up to 4.5 atm. So that the hot aqueous solution of adipic acid is kept in a stable state, it is preferred to put the hot aqueous solution under pressure by means of an inert gas such as nitrogen, helium or argon. The hot aqueous solution of adipic acid is sprayed in from a nozzle summed with a hot aqueous solution of adipic acid which is attached in the central part of an injection opening for injecting the ammonia as a gas stream due to its intrinsic pressure. In this case, it is preferred to introduce the hot aqueous solution of adipic acid into the fluidized bed at a point at the passage through which the ammonia gas is introduced as a gas nozzle.

In the preferred embodiments, all nozzle For spraying in a hot aqueous solution of adipic acid, an atomizing device or atomizing device is used, which consists of a Kusseren tube (for introducing the ammonia to be injected) and an inner tube Tube (for the introduction of a hot aqueous solution of adipic acid). In this embodiment, η becomes

009834/1933

■ »ο · ■

Ammonia gas from one end of the outer tube by means of A fan is fed simultaneously when the hot aqueous solution of adipic acid from one End® of the interior Tube is fed by means of a pump, and the atomization the hot aqueous solution of adipic acid is carried out with the aid of the ammonia gas fed in from one end of the pipe or the ammonia- gae is connected from one end of the inner tube (to the management of the ammonia to be injected) by means of a fan fed at the same time that the hot aqueous solution of adipic acid was fed from one end of the outer tube (for introducing a hot aqueous solution of adipic acid) is introduced by means of a pump, and atomization of the hot aqueous solution of adipic acid is carried out carried out with the aid of the ammonia gas supplied from one end of the inner tube.

It is possible to use the Durohmesser in the desired manner the nozzle for spraying the hot aqueous solution of adipic acid and the amount of that sprayed from the nozzle to change aqueous solution of adipic acid.

The loading ratio of ammonia gas versus the adipic acid is higher than the stoichiometric ratio. Namely, ammonia gas is introduced in an amount greater than 2 hol per mole of adipic acid. Is preferred it, the ammonia gas in an amount of 10 to 50 moles each To introduce moles of adipic acid. In the context of the invention part of the ammonia gas preheated to a high temperature into the fluidized bed through a funnel-shaped Manifold introduced at the bottom of the fluidized bed and the remainder of the ammonia pasea, which has been preheated to high temperatures, is poured into the

009334/1933

Fluidized bed as a gas stream through sine in the middle Lindüsöffnuiag attached to part of the distributor was introduced.

The volume flow rate igk @ i test, äes entire

Ammoniakgaseaj the gas nozzle stream and through the funnel-shaped distributor going Asaiaonialcgasss "aiii of the ammonia gas by atomizing eggs

Solution of adipic acid are _{indicated as To 9} Y _rs Y ₇ , and ¥ _fi Std.) @ B © n§. the linear velocity of the gas flow is ₉ if it is given by ₈ as Uj (a / sec.) (calculated on the velocity b @ i of the temperature of the opening) _f and di © e £ ur © ii * - Average surface velocity over total ammonia in the empty column is given as TIö (svWk.) (calculated on the gas velocity at the temperature in the fluidized bed) and 3) are the following relationships between the above factors?

Vo β

üo = Yo 273 + t ^U J ⁼ "fs ² 273 V . 273 + t » Hd ² 273

009834/1 933

BATH ORIGINAL

Here, t means the temperature ( ⁰ C) in the fluidized bed and t * means the temperature ( ⁰ C) of the grass nozzle flow at the injection opening, the effective diameter d being given by the equation d «/ d, j -dg, where d «Represents the diameter of the injection opening and d« represents ^the diameter of the nozzle installed in it.

The average final linear velocity of the solid catalyst borrowings in the upper part of the fluidized bed is calculated as Ut (n / sec.) (Back to the rate at the temperature of the ammonia gas in the bed) is given.

In the process according to the invention, the linear velocity Uj of the gas nozzle flow must be higher than the surface velocity in the empty column Uo and must be high enough that the dehydration catalyst cells flow in convection flow and circularly in the fluidized bed.The preferred ratio is Uj / Uo, although it is more or less depends strongly on the particle size of the dehydration catalyst, generally in the range from 1.1 to 30, in particular 5 to 25. The superficial velocity in the empty column Uo must be high enough to bring the particles of the dehydration catalyst into the fluidization state, and the preferred range of surface velocity in the void. . Column Uo is generally 0.1 to 10 m / sec., Although it is more or less dependent on the average particle size and the size distribution of the catalyst particles. It is preferred that the ratio Vj / Vo of the volume flow rate Vj of the gas nozzle flow to the Volume flow velocity Vo of the entire Aiuioniak-

009834/1933

gases in the range from 0.1 to 0.7 _{V, in} particular from 0.2 to 0.4. In order to prevent the occurrence of the so-called blowout phenomenon in the fluidized bed and to keep the forced convection flow and circular flow of the catalyst particles stable in the fluidized bed, it is preferred to regulate the ratio of Uj / U «to below 3.

One of the features of the invention resides in the use of a funnel-shaped manifold which is connected to a Injection opening for injection at high temperatures preheated ammonia gas as a gas nozzle stream in the central part and with a spray nozzle for spraying a hot one aqueous solution of adipic acid, which is attached in the central part of the injection opening, is equipped. if Part of the ammonia gas β, which has been preheated to high temperatures, is injected as a gas jet stream from this opening at the linear velocity specified above, the catalyst particles in the bed become a circular and convection movement in the bed in the catfish « forced the particles in the middle of the bed to have upward currents and those in the vicinity down the wall of the bed form currents directed downwards can effectively prevent stagnation of catalyst parts in the vicinity of the wall of the bed will.

In general, it is preferred that the ratio d / D from the effective diameter d of the injection opening to the inner diameter Z) of the entire column, i.e. dta diameter of the fluidized bed β, la Btrtioh from 1/2 bi 1/15, although it is more or less different from that Particle size and the particle distribution of the catalyst

009834/1933

BATH

dependent 1st. Furthermore, it becomes from the viewpoint of preventing the solid catalyst particles from stagnating prefers to use a funnel-shaped distributor with a sawing angle of 45 to 60 °. The total diameter sensor and the open area of the distributor can easily be determined by simple experiments on the particle size of the catalyst and the linear velocity and the volume flow velocity determine the ammonia gas.

All usually in the intended order » solid dehydration catalysts used can be used in the present invention. For example, silica gel, boron phosphate, solid phosphoric acid catalysts and similar catalysts are used as dehydration catalysts in the context of the invention · The average size of the catalyst particles is preferably in the range of 0.1 to 2 mm. By Using catalyst particles with a size in the range from 0.1 to 0.5 mm it becomes possible to reduce the amount dee to reduce the amount of ammonia to be added.

The reaction for the preparation of adipic acid nitrile from adipic acid can be carried out under conventional conditions known to those of us. The reaction tempera door is 250-550 ⁹ C. Temperatures of 350 to 4oC ⁹ C being particularly preferred "Di · reaction temperature can by aussereβ heating under application of electric heaters or Heizaedien or by internal heating means of heating elements which are inserted into the fluidized bed, maintained · The procedure can be carried out under a pressure of subatmospheric pressure up to slight! Be carried out Uberatuosphttrendruok ·

009834/1933

BATH

In the context of the invention, as above

(J

wrote, a! rope of the ammonia gas preheated to a high temperature as uasdüsenstrom τοη an injection opening injected into the middle part of the funnel-shaped More expensive is attached, and thereby a "forced convection and circular movement of the solid catalyst particles caused by this gas jet stream. This movement keeps them in the fluidized state located catalyst particles in the fluidized bed Moments in the axial direction of the fluidized bed and restrict their movement in the radial direction, thereby causing the catalyst particles in the fluidized bed to be in convection flow and circular flow flow. When one is called aqueous solution of adipic acid from a nozzle for spraying a hot aqueous solution of adipic acid which

lies) in the central part of the opening of the gas nozzle streamf to the Catalyst particles sprayed in under this forced convection and circular movement due to the ammonia gas the hot adipic acid aqueous solution is uniformly dispersed within the bed * Regarding the water of the aqueous solution is volatilized on the dispersed hot aqueous solution of adipic acid, the adipic acid melts and then evaporates and the reaction between adipic acid and ammonia gas is carried out in the presence of the dehydration catalysts, where the formation of adiponitrile results in high purity and in high yields

For further explanation, the invention will be described below with reference to the attached schematics Drawings explained, the examples of pre-

00983A / 1933

show directions that can be used in the method of the invention.

An aqueous solution of the adipic acid is transferred from a dissolution tank or storage container 1 to the fluidized bed 4 through a nozzle 3 "to spray a hot aqueous solution of adipic acid in the central part of a funnel-shaped distributor 5 is attached, which is at the bottom of the fluidized bed 4, by means of @iner Pump 2 sprayed.

The hot aqueous solution of the sprayed into the fluidized bed 4 solution of adipic acid occurs at high temperatures in contact with said serving as Fluidisiermlttel ammonia gas 9 "that is preheated to high temperatures, and is injected through a Fluidisiergasblaarohr 7 the funnel-shaped distributor 5 _9, the ammonia gas 10 high temperatures are preheated and through a nozzle opening 6, which is attached in the central, funnel-shaped distributor 5, a gas = nozzle stream is injected so that the solid catalyst particles (not shown) flow in the bed in convection and circular currents. This causes evaporation of the water from the aqueous solution of adipic acid, the melting and evaporation of adipic acid and the reaction between adipic acid and ammonia, which result in the formation of adipic acid nitrile «*

The adiponitrile formed is in the gas state from a ffas outlet opening 8, which is in the upper part of the fluidized bed 4 is attached, removed and separated in a manner known per se. Part of the existing Catalysts sometimes also flow out of the gas outlet opening 8, but it is possible to Amount of catalyst in the bed by adding

009834/1933

for the catalyst in the fluidized bed spread constantly to keep.

One of the features of the invention is that a hot aqueous solution of adipic acid _{is sprayed from a nozzle 3 for spraying a hot aqueous solution of adipic acid t} which is attached in the central part of a funnel-shaped distributor 5, which is at the bottom part of a fluidized bed 4, and «In Heil an ammonia gas preheated to high temperatures is introduced as a gas nozzle stream from an injection opening 6 which is attached around this spray nozzle 3 . Because of this feature, a sufficient and uniform contact can be between the hot aqueous solution of adipic acid, the ammonia gas and the catalyst particles are ersielt and the reaction can proceed efficiently, so that it is possible Adipinsäurenitril bit a purity higher than 9fy in yields higher than 94, 6jt to create

In the drawings, the circuit of the catalyst particles started in the fluidized bed.

In Pig. 1 is a look, dl an execution

For a device that can be used in the practical implementation of the method according to the invention, 2 shows a further view of a further epesific modification of the device according to FIG. 1 seigt.

In the geseigten in flg. 2 is AusfÜhrungsfom • ine sputtering apparatus 12 sua spraying "iner h" eat "n aqueous solution of adipic mm central portion united funnel-shaped distributor 5 exist. This atomizing or atomizing device consists of an interior

009834/1933 BADORlGtNAt,

Tube 13 and an outer tube 14 · Di «hot aqueous Solution of the adipic acid is passed through the inner tube 13 and then uniformly into the fluidized bed 4 from the spray nozzle 3 with the aid of the nozzle introduced through the outer tube for atomization and from the injection opening 15 embedded ammonia gases are atomized.

The adiponitrile can be obtained from the reaction product in a manner known per se. In particular, the reaction product is removed from the reaction vessel in the gas state, the adiponitrile through the first cooling separated and recovered, then the non-condensed material of a second cooling for separation and removing the by-produced water and the unreacted ammonia as it is or after purification to the basic stage of the production of the Recirculated adiponitrile.

According to the invention, an extremely uniform Contact between adipic acid, ammonia and catalyst particles can be achieved. Due to the presence of τοη Steam in the bed also makes it possible to produce adipic dinitrile of high purity in high yields without any substantial decrease in the activity of the catalyst even after slow operation. Furthermore, according to the invention, the sticking of adipic acid on nozzles, reaction vessel walls, distributors and the like · full «· are constantly prevented · D * it is still not necessary to add the adipic acid and ammonia at low temperatures when adding the adipic acid To keep the fluidized bed, it is not only possible keep the temperature in the fluidized bed constant, but also dl · Snthalpl · the reaction · participants, the In

009834/1933

BATH

the reaction system introduced to increase.

The following examples serve to further illustrate the invention. The amounts of impurities in adipic acid nitrile, such as the cyclopentanone formed by thermal decomposition of adipic acid and Cyanilinej were made on the basis of the quantities consumed determined on potassium permanganate.

example 1

4 l of a boron phosphate catalyst with a diameter of 0.5 to 1.0 mm were placed in a fluidized bed ™ with a diameter of 100 mm and a length of 1500 mm and equipped with a funnel-shaped distributor with an angle of repose of 45 ° · Ammonia gas serving as fluidizing agent from the distributor in an amount of 12.8 Hm / hour. and injected ammonia gas on the injection opening (12.6 mm effective diameter) in an amount of S ₉ A Hi / Stä, were introduced into the fluidized bed land © ine hot aqueous solution of adipic acid with a concentration of 80 $, ie at 120 ⁰ C and 2 atm was kept, was in the fluidized bed in an amount of 5.20 kg / hour. from a nozzle 2 mm in diameter for spraying a hot aqueous solution | of the adipic acid, which was present on the central part of the distributor, with the aid of the ammonia gas used to atomize the hot aqueous solution of adipic acid in an amount of 2.0 HmVh. (200 "C) sprayed diethylene reaction took place at 400 ⁰ C. The entire ammonia gas used had been preheated to 400 ¹¹ C. The linear velocity of the ammonia gas were as follows..:

009834/1933

1 1

Ii

θ / θο @ ε / ooe.

Bio

Sio H © Eg © i @ g fts a

A gg in the £ ämgsr © ii |? © alt

in Safeeiio 1 agg

treaat ame

s »as

®iiagefSls>% o lisio MeISo

from the

© likes log "
eiso bis ©

S ϊϊξϊ

ioo © iaos ⁴

iaon fe ©

f © @ Ms 3 © S ^

@is ieo

rubbish

bell® 1

isaä iaaa am. © äsaoia

Sat

00Ü34 / 1S33

BATH ORIGINAL

mm HuIdI-

Beep. 2 Example 3 Β 1 ρ.4 Example 5 Β ίβρ.6 Ββΐβρ.7

300 3400

1000 8100

300 3400

300 3400

1000 8100

53.9 10.5 52.9

206

10.5

2Q5

53.9 10.5 52.9

53.9 10.5 52.9

206

10.5

205

duroh water TOB

• l «ktrl- • oh ·· Sr * hitetn by Wft ·» er Ton mam »* n

«Lektriech · 8 Erhitmen 4 ·« B «tt * e and through Vaaaer tob, auaa» n

«L« ktri »β before β £? <- hit by« Waa * «er ron

L- electric Er- ache® Srhitsesj, hit2® & dos aursh Waa- Bettes and aer τοπ by Waassr

22nd

327

22nd

327

str * (: mm Sasatiee »- 0.5 10 165 10 1 © 169 se) "" "^ 1 6th 108 . ■ 6 ^{> G <} ■ 6 10 © fff) 3.3 3.1 3.35 3.05. 3.0 'S Ώ
^, ^ Vo im / m 0.42 0 _f 5 0 _f 68 0.49 0 _ff 48 O »© 7

Tab !! I (continued) For »p" 2 Example 3 Example 4 Example 5 Btiep-6 3 «i» p _e '

tar «! ·

(Boron phosphate) aenee (1)

100-500 100-500 5.3 118

100-500 100-500 100-500 100-500 3180 96 114 2830

OJ «Ο

> ffl

Ö * »

flw

(kg / h)

1.8 26th 540 21 24 510 0.1 1.4 28.4 5.25 2.9 61.7 95 95 95 80 89p3 89.3 130 130 130 115 125 125 3 2 5 2 2 3

! •• Jcttonet * ÄX> eratur (T) 380 3 400 370
92.6 14.3
92.1 380 5 342
90.6 Adltx acid nitrile kc / 8td.) 1.24
93.1 17.3
90.0 0.3-0.5 0.1-0.3 16.1
90.6 Usage ds? Yield ( yani «1n- 0.2-0.5 0.1-0, 0.4-0 _s 7 i W 0.1-0, gfihmli ü @ m Ws®ävik% 9a

ι Borehiut98fr the Μ © β sum spraying the hot aqueous adipine acidic elueiaBg, ■ ■, ■

t Wi ^ koÄKsr B% areh »er of the injection

1311263

200 to

Sos ³ hol 330 ^ 3 gökaltea uarlo ms «1 eiao Cteil © QO a- laat-SQp wueög sit © iasm boi 390 ⁵ S go Asmosaiakgss la" eise © laagea HQ®li% l @ ssi ⁱ © ia £ '

^] p © it © Im © ^ IsSsige ¹ ^ Oa 1300 @h mat v © si 100 mia fl ^ Mlslo ^ tp ias sit eiaoü 'lsi

f8r-äß © a

ait einsa BSseteasigouialsai? ea 45

flea UeiP'öoilQE ¹ is eiü & es QQ @ © te? ia © igkQit v @ e O ₉ S Ώεγ / Stä SiS iiS2? @k € iQ © • ssitgJQnstE ^ mGlaätsSffsaiaäig si'l oiiaera üiu

• fesileEO sxigGlsaekt ifa ^ e ia ®imm & Mcsag © van 3 ₀ ö la '/ i

¥ _? C.

6 "9 s / oo @

2 as sms? @ Keo0 © os? fite äi © keiSo ui Äig) öqs sms ¹ SorstiO / yiliiiisg with 20G ^ S psiffii-So Bio h © £ Sö

© 22.iml2 giss it

s ^ ¹ in

tns2? i © ni isi oisioa

0-0 I m kj 18 3 3

BATH

of 1.05 kg / hr (yield $ 79).

From this comparative example it can be seen that if the relative volume flow rate falls Gas nozzle flow is as large as V, / Vo and is 0.75, the yield of adipic acid nitrile is reduced.

Example 8

80 1 of a Silicagelkatalysators held at 380 ⁰ C with a size of 100 to 500 yes was held at 380 ⁰ C ammonia gas in a long reaction tube from the electrical Heiatyp with a length of 3400 mm and a Durehmesser of 300 mm, equipped with a funnel-shaped manifold equipped with a slope angle of 45 ° · fluidized the 380 ⁰ C heated ammonia gas through the manifold in a Ge "speed of 22 Ma? / Zt &, and by a © EindüeVffnune than grass jet stream with an effective diameter of _52? 9 mm placed in the central part of the manifold at a rate of 10 Mnr / hour. separately introduced The linear velocities of ammonia gas were as follows

Uo (380 ⁰ C) 0.48 m / sec Uj (380 ⁰ C) 3 _t 0 m / sec

A small aqueous solution of Adipineäas ® ® (mipic acid »26 kg / h water« 1.4 kg / Stlo), fii® had been brought to 2.5 atmospheres pressure and had been brought to 130 ⁸ C © rlaitat Was ₉ was in the vortex catalyst bed with the help of an ^{atomization gaiialtenaa at 200 0} g, which leads in an amount of 6 Hsr / h

009834/1933
BATH

from 18 to 1 kg / hour from the reaction vessel coming from the era Separated vapor (yield 94 *).

Example 9

The experiment according to Example 2 was continued for a period of 30 hours Test performed, with example 2 being repeated, but according to the teachings of American patent 3 242 204 (powder process) adipic acid powder instead of the aqueous solution of adipic acid, a vertical reaction vessel of the electric heating type with a diameter of 100 sub and a length of 1200 bus, the old a flat distributor and an opening for supplying the adipic acid powder in the vertical direction was used cubic fluidized bed and the ammonia gas for conveying the adipic acid ^{powder was kept below 50 0} D and supplied with a small amount of nitrogen gas to prevent solid or melted adhesions of the adipic acid t was

Table II

93 *
93 * Operation »* elt 30 hours 8 hours 88 *
78 * Example 9
HsI proceed 92 *
85 *

009834/1933 BAD

From the values of table II it can be seen that the inventive method * where adipic acid is supplied in the form of an aqueous solution and part of the Ammonia gas as a gas jet stream from an injection opening, which is attached in the central part of a funnel-shaped distributor, is injected, compared to the known Powder method in terms of persistence of catalyst activity is clearly superior.

009834/1933 BAD ORIGINAt

Claims (1)

Claims 1, process for the production of adipic acid nitrile, characterized »that adipic acid and ammonia are ^{reacted at temperatures of 250" to 550 0} C in a fluidized bed of a solid dehydration catalyst fluidized by means of ammonia gas, with part of the ammonia gas preheated to high temperatures in the fluidized bed a funnel-shaped distributor attached to the bottom of the fluidized bed is introduced, adipic acid in the form of a hot aqueous solution is sprayed into the fluidized bed through a nozzle for spraying a hot aqueous solution of adipic acid, which is attached in the central part of the funnel-shaped distributor, and the rest is sprayed on high ⁴ Temperatures preheated ammonia gas into the fluidized bed as a gas nozzle stream from an injection opening, which is attached in the middle part of the funnel-shaped distributor and around the nozzle for spraying the hot aqueous solution of adipic acid, at a higher linear speed it is injected as the average surface velocity in the empty column (Uo m / sec) of the total ammonia gas, so that the dehydration catalyst in the fluidized bed flows in convection and circular flow » 2, method according to claim 1, characterized in that a linear speed of the Gaadüaenstromee (Uj m / sec) between 1.1 and 30 times the average Surface speed (Uo m / eec) applied will. 3, method according to claim 1 or 2, characterized in, that a volume flow rate 009834/1933 dee gas nozzle current (Yj Hnr / h) between 0.1 and 0.7 times the volume flow rate of the whole Ammonia gas (Vo Sar / hour) is used. 4. Process according to Claims 1 to 3, characterized in that a solid dehydration catalyst with diameters in the range 0.1 to 2 mm are used will · 5. The method according to claim 1 to 4, characterized in that an ammonia gas injected as a gas nozzle stream, which is preheated to a temperature of 250 to 55O ⁰ C, is used. . 6. The method according to claim 1 to 5 »characterized in that a preheated to 80 to 145 ⁰ C hot © aqueous adipic acid solution is used. 7 * Method according to claims 1 to 6 _S characterized in that a hot aqueous adipic acid solution is used above its own vapor pressure of up to 5 kg / cm by means of an inert gas "s below B2? U @ kg® =" 8. The method according to claim 1 to 7, characterized in that the hot aqueous solution of adipic acid in the bed by means of a funnel-shaped at the central part i @ ©. Distributor attached ZerstäubmgsTOS '' - direction using ron ammonia gas for atomizing the hot aqueous solution of adipic acid, which ame οla®ei part ia the bed to be introduced ammonia gas © @ i s - = θ shares and is preheated to up to 200 ⁰ C, Zürailrnkt will" 009834/1935 BAO ORIGINAL Blank page